We have 2 Cottage style house with a single tube size hole on a door that slides up and door on grooves from the upper right at about a 45 degree angle.

Yesterday I found bark dust piled at the bottom of the ‘V’ where the door stops. As I slid the door up there was more dust inside along with what looked like cotton.

These are 6′ off the ground. I cleaned them out.

This morning there is more cotton inside. I did see a small yellow jacket carrying cotton like material on the mason bee structure. After cleaning it out several times and perhaps because the weather has become cooler the cotton is no longer showing up inside. I actually saw a yellow jacket carrying a tuft of cotton like material. Please let me know if I should bring the two houses into the garage until it the yellow jackets are gone for the year.

Chris

Great pictures. I am not too sure who the culprit is here. Several mason beekeepers have sent me pictures with cotton in and around nesting tunnels. We are still searching for the culprit!

I put boxes out for summer bees this year but got none. I did however get loads of Mason Wasps. I retrieved the cocoons from the boxes and found that the cocoons look like little cigars with a dark brown color. They are brittle compared to Mason Bee cocoons and contain Larva. Do they overwinter as larva and develop next summer? Can they be stored as Mason Bees? Thanks Norm Z.

Hi- I have seen these before, but never knew that these were wasps. If in the fall it is still a soft-bodied undeveloped wasp, I would expect them to develop in early summer months as temperatures warm up. This is where the petri-dish comes in handy. Place cocoons in a petri-dish adjacent to a wet paper towel. Keep it on the countertop and see what emerges.Thanks Margriet

I just unwrapped a straw from this summer and in it I found 4 compartments separated with Sticky reddish Brown resin. In each compartment attached to the resin plug was a glob of soft yellowish material with a white larva which seemed to be attached to the glob on both ends.

These were in a straw suited for summer bees. The larva varied in size from about 1/8th to ¼ inch long.

Would you have any idea what these might be? This is a photo of the resin and the larva. Thanks Norman Z.

Thank you for the pictures Norm. I do not know what this is. It looks like the resin is anchored in the resin. If you can, keep it in a petri dish with some moisture and see what emerges. Margriet

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